Valve for steam-engines



rn srs ADDISON CROSBY, OF FREDONIA, NEW YORK.

VALVE FOR STEAM-ENGINES.

Specication forming part of Letters Patent No. 25,248, dated August 30, 1859; Reissued March 6, 1860, No. 921.

To all whom t may concern:

Be it known that I, ADDISON CROSBY, of Fredonia, in the county of Chautauqua and State of New York, have invented a new and useful Improvement in the Induction and Eduction of Steam To and From Steamn Engines; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming part of this specification, in which- Figure 1, is a transverse section of the valve. Fig. 2, is a longitudinal view of the same. Fig. 3 is a central longitudinal section of the cylinder of a steam engine, showing the manner of applying a set of such valves for induction and eduction.

Similar letters of reference indicate corresponding parts in the several figures.

My invention consists in the employment as an induction or eduction valve in a steam engine of a valve of the rolling or oscillating kind constructed as hereinafter described with an opening through it and with two opposite faces eccentric to its axis of oscillation, so that it is perfectly balanced as soon as it commences to move and all the while it is in motion, works without friction, and is kept close by the pressure of steam.

To enable others skilled in the art to make and use my invention I will proceed to describe its construction and operation.

A, (Figs. 1, and 2,) is the valve composed of two eccentric segments united at one or both ends and provided with a journal y', at either or both ends to work in a suitable bearing in the end of the valve box or side of the steam chest which contains the valve seat. The faces c, a, ofthe two segments are described from two different centers b, Z), Fig. l, which are equidistant from but on opposite sides of the center of oscillation c, of the valve and their eccentricity to the center c, is made apparent in Fig. 1, by the representation of the red circle which is concentric with the center c. Y

(l, is the opening through the valve extending nearly from one end to the other, between the two eccentric segments.

The seat for this valve has two faces e, e, which correspond in form with the faces a, a, of the valve so that the valve may it steam tight therein, and in each seat there is a port j'. I propose generally to make the seat in a box which can be inserted within the steam chest or other place where the valve is to be used and removed therefrom with facility.

In applying my improved valves to a steam engine a set of four is necessary, viz, two for induction and two for eduction, the induction valves being arranged on one side and the eduction valves on the opposite side of the cylinder as shown in Fig. 3, where A, A, represent the induction and A, A', the eduction valves. The valve boxes B, B, which contain the induction valves have a somewhat different arrangement of passages in connection with their parts f, to the arrangement in the boxes B, B', which contain the eduction valves, but these arrangements of passages need no particular description as itwill be obvious to the engineer that the arrangement may be varied almost indefinitely. The direction in which the steam passes through the valves, ports and passages is indicated in Fig. 3, by arrows. It will be readily understood by ref* erence to the dotted outline of the valve in Fig. 1, representing it open, and by reference to the left hand induction and the right hand eduction valves in Fig. 3, that as soon as the valve is opened in the slightest degree it is entirely surrounded by steam and so perfectly balanced. It will also be understood by a comparison of the bold out-- line and the dotted outline of the valve in Fig. 1, that as the valve opens its faces leave the seat and that it is only while the valve is closed that it touches the seat, and hence it works without any friction but that of its journal or journals, which is inconsiderable, and without any wear of its faces. And it will be understood by reference to the bold outline of the valve in Fig. 1, and to the right hand induction valve and left hand eduction valve in Fig. 2, which are closed, that the pressure of the steam on the excess of surface presented by the sides g, g, of the segments of the valves will tend to keep the valve closed tightly. This excess of surface is however so slight that it causes comparatively little resistance to the opening of the valves.

Viiat claim is my invention 'nd. desire tween the S'eginent ilbstantiaiiy iiiiei to secure by Letters Patent, isdescribed;

The employment as an induction or educ- ADDQON CROSBY tion valve in a steam engine of'a rolling or K 5 oscillating valve composed of two segments Witnesses:

having their faces a, a, eccentric to its axis ALLEN HINCKLEY,

of oscillation and with an opening d, be- THOMAS VAN SCOTER. 

